microspheres made by crosslinking of polyvinyl alcohol with glutaraldehyde functionalized with yeast lysate

Microspheres comparable with yeast cells in size were obtained by the glutaraldehyde crosslinking of polyvinyl alcohol (PVA), whose 25 g/l water solution containing magnetite particles was dispersed in the isooctane/Span 85/Tween 85 medium. yeast cell walls were partially hydrolysed by sonication in formic acid near the boiling point. The microspheres were made targets for phagocytosis by the addition of yeast lysate to the crosslinkable PVA solution and a subsequent treatment of the freshly crosslinked microspheres with diluted yeast lysate. The microspheres were also made fluorescent when the emulsification medium saturated with fluorescent 2-aminopyrimidine derivatives was used. A protocol for phagocytosis assay using the thus modified microspheres was developed.